Corrosion inhibiting processes and compositions of aliphatic amines and diquaternary diamines

ABSTRACT

IMPROVED COMPOSITIONS ARE DESCRIBED FOR INHIBITING CORROSION IN SYSTEMS USING WATER AS THE HEAT TRANSFER MEDIUM. THE COMPOSITIONS ARE AQUEOUS DISPERSIONS DISPERSIONS COMPRISING AN ALIPHATIC LONG CHAIN AMINE AND FROM ABOUT 0.20 TO ABOUT 1 PART OF N-PHENYL (HIGHER ALKYL) LOWER ALKYL QUATERNARY DIAMINE PER PART OF THE LONG CHAIN ALIPHATIC AMINE. THE PROCESS OF PREPARING THE DISPERSION AND ITS USE TO INHIBIT CORROSION ARE ALSO DISCLOSED.

United States Patent CORROSION INHIBITING PROCESSES AND COM- POSITIONS OF ALIPHATIC AMINES AND DI- QUATERNARY DIAMINES Ronald M. Silverstein, Parsippany, N.J., assignor to Drew Chemical Corporation, New York, N.Y.

No Drawing. Continuation-impart of abandoned application Ser. No. 666,480, Sept. 8, 1967. This application Feb. 9, 1971, Ser. No. 114,055

Int. Cl. C02b 5/06 U.S. Cl. 252-180 13 Claims ABSTRACT OF THE DISCLOSURE Improved compositions are described for inhibiting corrosion in systems using Water as the heat transfer medium. The compositions are aqueous dispersions comprising an aliphatic long chain amine and from about 0.20 to about 1 part of N-phenyl (higher alkyl) lower alkyl quaternary diamine per part of the long chain aliphatic amine. The process of preparing the dispersion and its use to inhibit corrosion are also disclosed.

This application is a continuation-in-part of my copending application Ser. No. 666,480, filed Sept. 8, 1967, now abandoned.

This invention relates to the inhibition of corrosion in steam condensate systems and more particularly relates to improvements for maintaining dispersions containing long chain fatty acid amines used to inhibit such corro- S1011.

The technology of preventing corrosion of metallic surfaces in systems in which water is used as a heat transfer medium, in the form of steam or cooling water, has received considerable attention. By way of background, Kahlers U.S. Pat. No. 2,460,259 disclosed a corrosion inhibiting means in which an aliphatic amine, e.g. octadecyl amine, is used. Since most long chain aliphatic amines are only sparingly soluble in water, difficulty was encountered in maintaining the amine as a uniform dispersion in the form which the corrosion inhibiting composition is normally prepared and sold. To overcome this disadvantage, Maguires U.S. Pat. No. 2,712,531 discloses the use of octadecyl amine acetate to assist in preventing the long chain fatty amine, particularly octadecyl amine, from crystallizing into the solid phase. The use of such an amine acetate is not entirely satisfactory, because of suspected decomposition which yields a weak acid, and which may give rise to corrosion in the system. Denmans U.S. Pat. No. 2,956,889 discloses the use of aliphatic amines utilized in conjunction with ethylene oxide condensates of aliphatic amines as corrosion inhibitors. Haggards US. Pat. No. 2,564,758 discloses the use of primary rosin amines in conjunction with ethoxylated secondary amines. Cross U.S. Pat. No. 2,779,741 discloses the use of hydrocarbon monoamines and an ammonium salt corresponding to the formula:

wherein R is an aliphatic hydrocarbon group of 8 to 20 carbon atoms, X is a salt-forming anion and NEA represents a tertiary amine or a tertiary N-heterocyclic base radical. Kahler et al. U.S. Pat. No. 3,088,796 disclosed the use of aliphatic amines and complex ethoxylated amine salts represented by:

CH3 [R1 I- cmomo omcmo wherein R is an aliphatic radical, X is a halogen ion, and the integers a plus b total from 2 to 15.

It is an object of this invention to prepare a stable dispersions of a fatty amine for use as a corrosion inhibitor in aqueous systems.

Another object is to prepare a dispersion of aliphatic amine corrosion inhibitor compounds at a cost savings which were heretofore unobtainable.

Still another object is to prepare a dispersion of a corrosion inhibiting amine which dispersion can be diluted to use concentration with no deleterious effect.

Yet another object is the provision of a method of inhibiting corrosion by the use of such novel composition.

The invention accordingly comprises the processes involving the several steps and the relation and order of one or more of such steps with respect to each of the others and the product possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description.

1 have now discovered a method for inhibiting corrosion in steam condensate systems by the utilization of my new corrosion inhibition composition. This composition is prepared as a dispersion of (1) a long chain aliphatic amine, and (2) a diquaternary diamine of the formula:

wherein x+y to 13-17 1:2 to 4, and

A is selected from the group consisting of halide, hydroxy and nitrate ions; and water (3) is the thiId component.

Component (1) the long chain amine are fatty monoamines of the formula:

R-NH

wherein R is a saturated or unsaturated hydrocarbon group containing from 8 to 22 carbon atoms. Typical examples of such compounds include but are not limited to octyl amine, dodecylamine, octadecyl amine, lauryl amine, and myristyl amine.

Typical examples of compounds within the scope of component (2) include N-phenylstearyl-l, 3-propylene diamine quaternary dichloride, N-phenyl arachidyl-1,4-N- butyl diamine quaternary dibromide, N-phenyl palmityl ethylene diamine quaternary dichloride.

The third component is water which need only be of the grade utilized in industrial processes.

In my composition, I utilize from about 0.20 part by weight of the diquaternary diamine to about 1 part by weight of the fatty monoamine with from about to about parts of water, more or less as is needed to form a stable dispersion.

I have found that the long chain aliphatic amine can be uniformly dispersed in the water phase and prevented from agglomerating and separating out as solid globules or flakes, by the use of a small amount of the diamine dichloride. Whereas Cross utilized from 1 part to 6 parts of his monoquaternary compound to 1 part of the allphatic amine, I am able to keep the aliphatic amine dispersed sufficiently by the use of from only 0.20 part to about 1 part of my diquaternary diamine. Since the cost of the monoquaternary compounds and the diquaternary compounds are substantially the same, an economically noteworthy saving can be achieved by the use of my compositions, particularly in large systems.

The compositions of this invention are aqueous dispersion containing the long chain aliphatic amine, preferably octadecyl amine, and the diquaternary diamine, preferably of this invention may be packaged for shipment while hot, or allowed to cool no lower than their solidification points prior to such packaging.

The eifectiveness of using a typical diquaternary diamine to maintain a typical fatty amine, namely octadecyl 5 of N-phenylstearyl-1,3-propylene diamine quaternary d1- amine uniformly dlspersed has been evaluated and comchloride, with the balance of the composition essentially pared against a number of alternative compounds. Disperbeing water, although additional ingredients, such as a sursions were prepared by the foregoing preferred method factant, may be included when deemed advantageous. using 8 or 9 percent octadecyl amine and 1 or 2 percent The weight ratio of the aliphatic amine to such dlquater- 10 of various other compounds and the characteristics of nary diamine is preferably about 5:1. Such a dispersion the resulting dispersions and their ease of dilution, at a normally prepared by the manufacturer and shi ped to the ratio of 10 or to l, in distilled water (at about 120 F.) user. Normally, although not necessarily, the user dilutes were observed. The dispersions were considered to be satthe dispersion with from about 4 to about 24 parts of isfactory if no solid phase aliphatic amine separated water, generally 9 to 19 parts of water, to form a diluted 15 therefrom within 24 hours after dilution, i.e. use, occurred. dispersion which is thereupon injected into the steam This data is set forth in the following table:

TABLE I Dispersant for aliphatic amine Oetadecyl amine,

Name Percent percent Observance N-phenylstearylJ,3-propylene diamine 2 8 Excellent viscousmilk-whiteconcentrate;

quaternary dichloride. easily diluted in distilled water.

Do 1 9 Good concentrate but with some infrequent particles of octadecyl amine in the solid phase; difficult to dilute, with some separation of octadecyl amino particles.

Do 2 9 Excellentviscousmilk-whiteconcentrate;

readily diluted without phase separation for 24 hours.

Dodecyltrrmcthlyammoniumchlor1de 2 8 Very poor concentrate; waxy layer of {rctadfcyl amine appeared on top of lqlll Octadecyl trimethyl ammonium chloridc-... 2 8 Fair concentrate, with some particles of octadecylseparated out; poor dilution with additional amine separating out within 24 hours.

l-hexadecyl pyridinium chloride 2 8 o.

Ammonium chloride phenylstearyl tri- 2 8 Concentrate not homogeneous.

methyl quaternary.

Ammonium chloride diphenyl dimethyl 2 8 Very poor stability with large lumps of quaternary. octadecyl amine in concentrate.

Polyethoxylated (5) phenylstearyl methyl 2 8 Ineffective; octadecyl amine formed on quaternary ammonium chloride. surface of liquid.

2 8 Concentrate unacceptable, since octa- Polyethoxylated (15) phenylstcaryl methyl quaternary ammonium chloride decyl amine was dispersed as visible solid phase particles.

condensate system for the purpose of inhibiting corrosion therein. Typically, suflicient diluted dispersion is added as by a proportioning pump, to the system to provide in the range of from about 0.1 to about 5 parts per million of long chain aliphatic amine in the steam. The addition of the diluted dispersion may be made to the system at a point where the heat transfer water is in the liquid phase, e.g. to the boiler feed water, or to the water in the vapor phase, such as in the steam conduit downstream from the boiler.

The preferred process of making the aforesaid dispersion is to mix together the entire amount of diamine quaternary with about percent of the water to be used for the dispersion. This solution is heated to about 170 F. at atmospheric pressure and the aliphatic amine added to the solution while the solution is stirred or otherwise agitated and the temperature is maintained at about 150- 175 F. After the fatty monoamine has been dispersed in the solution, the remainder of the water, which is normally at room temperature, is added and the resultant dispersion is stirred while it cools to a temperature of less than about 125 F., after which stirring may be discontinued.

An alternative process of preparing the dispersion is to mix together the aliphatic amine and the diamine quaternary and then melting the two ingredients by heating them to about 120-125 F. The melted ingredients are added to the required amount of water, which is used at about 150-175" F. The mixture is then stirred while maintaining the elevated temperature until the desired dispersion has achieved a uniform homogeneous appearance. Thereafter, it is cooled to about 120-130 F., stirring being continued until such temperature is reached and thereafter stirring may be discontinued. The prepared compositions Since certain changes may be made in the above products, compositions and processes Without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A Water dispersible composition for inhibiting corrosion, comprising:

a long chain aliphatic hydrocarbon amine having from 8 to 22 carbon atoms and a diquaternary diamine of the formula 5. A process for inhibiting corrosion of metal surfaces in contact with an aqueous system, comprising:

adding to the aqueous system the composition of claim 2. 6. A process for inhibiting corrosion of metal surfaces in contact with an aqueous system comprising:

adding to the aqueous system the composition of claim 1. 7. A process for inhibiting corrosion in a steam condensate system, comprising:

adding to the steam condensate system the composition of claim 1. 8. A composition for inhibiting corrosion, comprising: a long chain aliphatic hydrocarbon amine having from 8 to 22 carbon atoms; a diquaternary diamine of the formula:

wherein x+y is 13-17 2 2 to 4, and A is selected from the group consisting of halide,

hydroxy and nitrate ions; and water, said aliphatic hydrocarbon amine and diquaternary diamine being dispersed in said water.

9. The composition of claim 8 wherein the ratio of diquaternary diamine to aliphatic amine is from 0.20:1 to 1:1.

10. The composition of claim 9 wherein the diquater- References Cited UNITED STATES PATENTS 2,779,741 1/ 1957 Cross 252390 X 2,460,259 1/ 1949 Kahler 117--97 3,397,152 8/1968 Brown 252-390 2,712,531 -7/1955 Maquire 252 2,956,889 10/1960 Denman 252390 X 2,564,758 8/1951 Haggard 252--8.55 3,088,796 5/1963 Kahler 21-2.7 3,3 82,186 5/1968 Silverstein 252-390 OTHER REFERENCES Chemical and Engineering News, Aliphatic Fatty Acids Marketed, vol. 44, page 21, Nov. 28, 1966.

ROBERT F. BURNETT, Primary Examiner M. E. MCCAMISH, Assistant Examiner US. Cl. X.R. 

